Blood vessels and neoplastic growth in the brain

Abstract

Cancer associated angiogenesis has been regarded for many years as essential for a tumour to grow. However the discovery that some neoplasm can also grow in absence of angiogenesis has demonstrated that the relationship between cancer and blood vessels is much more complex than previously believed. These non-angiogenic tumours grow by co-opting and exploiting the pre-existing vessels. Alongside lung, liver and lymph nodes, brain is one organ where both primary and metastatic malignancy can grow in this way. Among the primary tumours of the central nervous system those from the glia have been more extensively investigated.  Anti-angiogenic treatments have been tested but the results have not kept up with the expectations, one of the reasons being the ability of these tumours to exploit the normal brain vessels. Metastatic tumours to the brain are a common clinical event among oncological patients with poor prognosis and non-angiogenic growth has been observed also in brain secondary. Initial data from literature have started to show that vascular co-option by both primary and secondary malignancy is an active process involving pathways related to cell adhesion, motility and apoptosis. Detailed understanding of this process will possibly lead to new therapeutic approaches aimed to disrupt this modality of neoplastic progression. In this review it is presented a synthesis   of our current understanding of this intriguing relationship between vessels and tumours in the brain.